Field of the Invention
The present invention relates to a non-contact sensing module and a method of manufacturing the same that can sense a displacement of a brake pedal and apply a switching signal thereof to a control system or a peripheral device of a vehicle.
Description of Related Art
In general, vehicles use a non-contact proximity sensor that senses a displacement (separation distance) of a sensing object and applies a predetermined switching signal to a vehicle control system or a peripheral device.
The non-contact proximity sensor senses a displacement of a metal material that is installed at a sensing object using an inductance (L) component of an LC oscillation circuit and performs a switching operation according to a sensing signal thereof and representatively includes, for example, a brake switch that is mounted in a brake pedal unit.
Here, the brake switch senses a displacement of a brake pedal and applies a switching signal to a braking lamp, an electronic relay, a starting device, an engine control unit, a braking control unit, and a transmission control unit.
In order to recognize a displacement of a metal material that is installed in a sensing object, a non-contact proximity sensor has a printed circuit board in which a coil is formed.
When the metal material of the sensing object approaches the coil, the non-contact proximity sensor generates an eddy current at a metal material surface by an electromagnetic induction phenomenon, and the eddy current disturbs a flux of inductance that is applied from the coil to change a waveform of an LC oscillation circuit, and by appropriately determining such a changed waveform, the non-contact proximity sensor may output a switching signal.
However, a conventional non-contact proximity sensor forms only a coil for recognizing a displacement of a sensing object in a printed circuit board, and because a means for guaranteeing that a displacement recognition of the sensing object is accurately performed is not separately provided, a sensing performance and reliability of the sensing object is deteriorated, and stability of a switching operation is deteriorated.
Further, in order to improve a sensing performance of a sensing object by a coil, a conventional non-contact proximity sensor may form a coil at both surfaces of a printed circuit board, and a two-layer both surface structure cannot connect a start point and an end point of each coil to a circuit material of the printed circuit board with.
That is, in the two-layer both surface structure of the printed circuit board, because each coil is interfered, it is impossible to form a connection path that connects each coil and a circuit material.
Accordingly, in order to form a coil at both surfaces of the printed circuit board, a connection path of each coil and a circuit material should be inevitably formed with a multi-layered structure of a four-layer, and this may increase a thickness of the printed circuit board and increase a production cost.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.